Seriously, they both make fantastic cameras. Once you invest in a system it is hard to switch. You get used to the ergonomics of one over the other and you would have to sell lenses at a loss of course. So, my recommendation is to buy what your friends (or co-workers) have. The advantage of that is you will be able to borrow lenses and information/experiences which are both valuable. Also, while Nikon has had an advantage recently in low light cameras and Canon in video acquisition, they seem to catching up to each other in both. Though it does seem that Canon is probably the way to go if video is a first priority. On the other hand, the D600 seems to be a great way to jump into serious photography and will trump the Canon 6D since the latter has only a few autofocus points.